#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
int main()
{
    int a,b,c;
    cin >> a >> b >>c;
    if(a+b<=c || b+c<=a || a+c <= b)
        cout << "These sides do not correspond to a valid triangle"<< endl;
    else
    {
        float s = (a+b+c)/2.0;
        double area = pow(s*(s-a)*(s-b)*(s-c),0.5);
        cout <<fixed << setprecision(2) << "area = " << area << "; perimeter = " << s * 2;
        
    }
}